The standard of rust preventive oils is prescribed in JIS K2246, and the rust preventive oils are categorized into five types: a fingerprint remover type; a solvent cutback type; a petrolatum type; a lubricant oil type; and a volatile rust preventive oil. Further, three types except for the fingerprint removal type and the petrolatum type are further categorized into specific types depending on intended purposes and properties.
The rust preventive oils of the solvent dilution type, the fingerprint removal type, and the like contain a solvent, and exhibit a high rust preventive property when the solvent volatilizes and viscosity of an oil film itself increases or when the concentration of an additive, if contained, in an applied oil film increases. As the solvent of these rust preventive oils, kerosene which is easily available and cheap is widely used (for example, see Patent Literature 1). Further, alkylbenzene having high washability may be used (see Patent Literatures 2 and 3).